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Finding the Fourth Proportional to 78.81, 118.11 and 65.25

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Solution

The fourth proportional to 78.81, 118.11 and 65.25 is: 97.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    78.81 : 118.11 = 65.25 : x
  2. Step 2: Convert to fraction form
    78.81/118.11 = 65.25/x
  3. Step 3: Cross multiply
    78.81x = 118.11 × 65.25
  4. Step 4: Simplify right side
    78.81x = 7,706.68
  5. Step 5: Solve for x
    x = 7,706.68/78.81
  6. Step 6: Final answer
    x = 97.79

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.